Nature of the critical points of a function f(x y): local maximum/minimum/saddle and another ● 07
f(x, y) = -2 x⁵ y - 2y⁶ - 2x² y² + 2y³ + x³ + 3x² + 4y² + x y + x - y - 5
fx(x, y) = -4 y² x - 10y x⁴ + y + 3x² + 6x + 1
fy(x, y) = -2 x⁵ - 4x² y + x - 12y⁵ + 6y² + 8y - 1
fxx(x, y) = -40 x³ y + 6x - 4y² + 6
fxy(x, y) = -8 y x - 10x⁴ + 1
fyx(x, y) =-8 y x - 10x⁴ + 1
fyy(x, y) =-4 x² - 60y⁴ + 12y + 8
